You always hear of the “delicate, sensitive artist.” I assure you that it takes the nerves of a bullfighter, the digestion of a peasant, the vitality of a nightclub hostess, the tact of a diplomat, and the concentration of a Tibetan monk to lead the strenuous life of a virtuoso.
Jascha Heifetz (1901-1987) Lithuanian-American violinist
(Unsourced)
Quoted on his official web page.